Photovoltaic modules are partly mounted on support structures which follow the sun along one or two axes. The major advantage of this movable support structure known as “mover” over the tightly anchored ones is higher current efficiency with one and the same active module surface.
A very particular problem with larger surfaces which are installed outdoors resides, among others, in the wind forces which are also transferred to the adjusting means and which under unfavorable conditions which are to be considered will provoke excessive stresses in the latter.
Common adjusting means are mostly actuated by cylinders, gear segments, screws or equivalent elements the shared disadvantage thereof residing in the fact that torques caused by wind forces will be absorbed by way of relatively short lever-arms thus causing high forces in the adjusting means itself as well as in the anchoring sites.
Accordingly, an adjusting means is to be found the mesh points of which on the pivotable support structure are outwardly offset as far as possible, however, without oversized adjustment elements becoming necessary. One possibility would be by way of adjustment cables or comparable flexible traction elements which are mounted on the support structure to be pivoted. There are already known such systems which, however, suffer from the disadvantage of requiring circular segments which are concentrically connected to the pivoting axis and are connected to the support structure to be pivoted and whereon the adjustment cables will be wound on one side and accordingly will be unwound on the other side. Only with this kind of geometry it will be achieved that the cable length which is wound by the pivoting movement will be equal to that which is unwound in the case when the movement of the adjustment cable will be accomplished by a conventional continuous winch.
As mentioned above, due to static reasons, the mesh points of the adjustment cable must widely be spaced from each other. With the know solutions this distance corresponds to the diameter of simultaneously rotating circular segments, whereby such adjustment devices may take large dimensions. A further disadvantage of the conventional solutions wherein the adjustment cable is wound and unwound on circular segments, respectively, resides in that the winch must be mounted on the side which is turned away from the one having the circular segments in order to actuate the adjustment cable united on the pivoting part.
The publication US 2010/018566 describes a device for the transformation into a photovoltaic current including one or more balloons including gas which is lighter than air, with one or more solar energy panels on a basis, one or more solar energy panels which are mounted by one or more balloons, one or more balloons being mounted on one or more solar energy panels, wherein a weight is provided which, with one end, is mounted on one or more panels and which, with the second end, is mounted on a basis, wherein an electric charge tester is connected to a battery system for the adjustment of one or more energy panels; and a battery system for the electric charge.
The cable system described in this prepublication allows tracking panels on balloons as a support structure wherein length balancing of the cables is not required.
The European patent 0 114 240, on the other hand, shows tracking means for the precise or approximate tracking of devices according to an arcuate track, for example of solar technical receivers or reflectors, wherein movement of the device will be realized about two axes and movement of the device about the second axis is necessarily coupled to the movement around the first axis by way of at least one guiding element having a hinge point and the guiding element pivots about hinge point which, in relation to the major movement, is not simultaneously displaced and is located exterior of the first axis of the device, wherein the axes intersect and the guiding element is arranged such that the simultaneously moved hinge point moves at a circle point the center of which is the intersection of the axes and the connecting line between this intersection and the hinge point which is not displaced is exactly or approximately parallel to the axis of the earth or to the surface normal, respectively, of the track of the tracked object.
This tracking means is very complicated regarding to its execution and furthermore regarding to the support construction, due to the fact that bearing thereof on one of its axes may only be realized with expenditure and effort.